Self-taught here - both striding and skating. When I was 9 my parents borrowed skis from some friends, and Dad took us each out in the yard, one at a time (only 2 pairs) to see if we liked it. We did. When our own skis showed up, the poles were back-ordered, so we went out around the yard without them for a few days (which is a very very good way to learn technique!). My sister later turned to downhill (and lives in Texas now), but Mom & Dad and I are still at it, 35 years later.
It can definitely be done without lessons. I don't really agree that skating is more technique-driven, though. I think it is more strength driven, and so you feel it more if you aren't doing it correctly. Well, actually, I think you have to have the strength before you can have the technique, if that makes any sense. I've always thought striding was more technical - it's just that you can shuffle along from Point A to Point B with really poor technique. An awful lot of people really don't have any kick at all, and just shuffle. Which is fine, by the way, as long as it is fun!
I say, go out and give it a try, and then see if you want to take lessons later. Get a feel for the skis first, anyway, or you'll be wasting your time and money on a lesson, when you're just trying to get comfortable standing on the things that first time.
Have fun! :D

